We did a session when my child was 2 after multiple parks and rec classes (water was too cold). He was going underwater and swimming through hoops etc. The pool is warm so my child was willing to work at it. I pulled him out because we joined an athletic club w/ swim lessons, but my son just screamed the whole time in those lessons. Put him back at COTS when he was 3 1/2 and he had completely regressed. He wouldn't get in the water first couple of times, and then wouldn't participate much. After the first couple weeks he was doing much better because the instructor was wonderful at working with him and his needs. We are in our 3rd session and he's swimming on his own now. Amazing! The 2 instructors we've had were wonderful. I only wish I'd kept him in this school from the begining. They are great at working w/ your childs individual needs which is possible in their small classes (only 4 children per class, which a lot of the time is even smaller).